Hollow panel volume control for pipe organs



O United States Patent [1113,548,703

[72] Inventor George L. Payne 1,862,582 6/1932 Schlenker 181/31 1515 Bellevue Aw, Richmond, Va. 23227 1,929,626 10/1933 de Forest.... l8 1/(33.4) [211 App]. No. 791,442 2,477,852 8/1949 Bacon l8l/(33.l) [22] Filed Jan. 15, 1969 3,090,463 5/1963 Yanda 18 l/(33.02) [45] Patented 1970 Primary Examiner-Richard B. Wilkinson Assistant Examiner-John F. Gonzales s41 noLLow PANEL VOLUME CONTROL ron PIPE P semmes ORGANS 6 Claims, 5 Drawing Figs.

Us. Cl. A plurality of hollow panels for mounting 84/372 ,the sound opening in the swell box of a pipe organ, each panel 1 III. Cl. comprising a pair of spaced membranes and connected 0f to means for evacuating air therefrom The panels trans.

131/3392, 3304, 33-4, mit sound therethrough when the interiors thereof are at at- 33-14, mospheric pressure, and become at least partial nonconductors of sound when exhausted with a light vacuum. The sound I 56] Rgkmm Cited output of the pipe organ instrument is controlled by evacuat- UNITED STATES PATENTS ing one or more of the panels, the volume decreasing as addi- 1,234,086 7/1917 Powers 181/(33.4) tional panels are evacuated.

PATENTEU [103221970 SHEET 2 OF 2 INVICNI'UIL GEORGE L. P/iY/VE J HOLLOW PANEL VOLUME CONTROLFOR PIPE ORGANS BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates generally to pipe organs, and more particularly to a panel construction for mounting within the sound opening of a pipe organ swell box for controlling the volume of sound emitted.

2. Background of the Invention The sound-generating pipes of a pipe organ are commonly designed to emit only a single volume of sound, and thus resort must be had to auxiliary apparatus if varying volumes are to be obtained from the instrument. To this end, the organ pipes are conventionally mounted within a swellbox having an opening therein through which sound is emitted. The organ sound volume is controlled by utilizing means to control the volume of sound that is emitted through this sound opening.

At present, control over the amount of sound emitted through the swell box sound opening is obtained by mounting a plurality of movable shutters within the opening. When the shutters are all closed, sound emission is at a minimum. The instruments volume is increased whendesired by opening one or more of the shutters, the loudest possible organ sound being obtained when all of the movable shutters are in an open position. i

Various constructions for movable swell box shutters have been proposed. However, the mere fact that the shutters are movable requires hinged or pivotal mounting thereof, and necessitates some sort of mechanism to operate the shutters between their open and closed positions. The shutter mountings and the opening and closing mechanisms are subject to wear and breakdown over the life of the pipe organ instrument, and there is thus need for an arrangement with no moving parts capable of controlling the volume of sound emitted from a swell box. The present invention satisfies that need.

SUMMARY OF THE INVENTION The panel of the present invention is constructed so that when it is in a normal or positive pressure-state it will freely transmit sound therethrough, and so that when it is in an evacuated state the sound transmitting properties thereof will be greatly lessened. Several such panels are mountedin sideby-side abutting relationship within the sound opening of an organ swell box, and by controlling the states of the panels, the volume of sound emitted by the instrument can be controlled. Specifically, the panels can be operated altogether simultaneously, to provide a change between maximum and minimum organ volume, or they can be operated singly or in various combinations to produce desired levels of sound.

Each hollow panel is airtight and comprises a relatively rigid supporting structure on the opposite sides of which parallel, stretched membranes are mounted. In the preferred embodiment the supporting structure comprises-a hollow rectangular frame several inches thick, within which "a honeycombed element is received. Taut membranes of thin plastic are sealed to the opposite sides of the supporting frame, and the frame has a port thereon to which air exhausting means is connected.

Normally, the interior of the hollow panel is open to atmosphere, through the panel port. In this state air pressure is balanced on the membranes, and the panel will operate to freely transmit sound therethrough.

When it is desired to lessen the sound transmission properties of the panel, air is evacuated therefrom, the honeycombed core functioning in the presence of a vacuum to hold the membranes against inward flexing whereby the volume of the panel is maintained relatively constant. In the invention the panel is normally evacuated to about I to S-inches water pressure on a manometer, the degree of nontransparency to sound increasing proportionately with the degree of evacuation. When full sound transmission is again desired, the vacuum is released and the panel interior is opened to atmosphere.

It is a principal object of the presentinvention to provide a panel with no moving parts, that can-be operated to shift between a first state wherein sound is freely transmitted through the panel, and a second state of lessened sound transmission capability.

Another object is to provide an assembly involving no movable elements for mounting within the sound opening of an organ swell box, operable to control the volume of sound emitted by the instrument.

A further object is to provide an assembly of the type described, comprised of a plurality of panels that can be operated separately or in any desired combination to produce a plurality of organ sound volume levels.

Other objects and many of the attendant advantages of the present invention will become readily apparent form the following description of the preferred embodiments, when taken together with the attached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of an organ swell box having a plurality of the present panels mounted within the sound opening thereof, the swell box being partially broken away to show the organ pipe assembly mounted therewithin, and the panels being of equal width;

FIG. 2 is an enlarged sectional view taken on the line 2-2 of FIG. 1, showing the construction of oneof the panels and the valve and vacuum manifold assembly for operating the same;

' FIG. 3 is an enlarged vertical sectional view taken on the line 3-3 in FIG. 1, further showing the construction of the present panels;

FIG. 4 is a perspective view of a portion of one of the honeycombed cores received within the panels of the invention; and

FIG. 5 is a perspective view of a second embodiment of the invention, utilizing three panels of different widths which can be operated in different combinations to provide various levels of organ sound.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to FIGS. 1 through 4 of the drawings, an organ swell box is indicated at 2 and includesa front panel 4 having a large, rectangular sound opening 6 therein. Mounted within the swell box 2 are organ pipes 8, which are operated from the organ console (not shown) to produce soun'd. While the present invention is principally concerned with pipe organs, it is to be understood that sound emission means other than the organ pipes 8 might be employed within the swell box 2.

Mounted within the sound opening 6 of the swell box 2 is a panel assembly 10, comprised of a plurality of sound panels 12 constructed according to the invention. The sound panels 12 are all identical, and each includes a hollow rectangular frame 14 comprising top and bottom walls 16 and 18, respectively, joined to end walls 20. Typically, the supporting frame 14 will measure about 5 feet in length by about 6 inches in height, and will be about 5 inches thick.

Received within the hollow frame 14 is a substantially rigid I honeycombed core 22, made of plastic, wood, or some other suitable material. The honeycombed core 22 has a thickness identical to that of the frame 14, and is constructed with connecting internal passages arranged so that air is freely passable therethrough. A portion of a typical core 22 is shown in perspective in FIG. 4, but it is to be understood that other core configurations than that shown in FIG. 4 can-be utilized.

Stretched taut on the opposite sides of the hollow rectangu lar frame 14 are membranes 24, made of thin plastic about 2 mils in thickness, or some other suitable material. The edges of the membranes 24 are sealed to the frame 14, whereby to form an airtight sealed chamber within each hollow panel 12.

The six panels 12 are secured within a rectangular mounting frame 26, the latter having a peripheral flange 28 thereon and being receivable within the swell box sound opening 6. The

panel assembly 10 is mounted within said opening 6, and is I-Iowever, if the interiors of the panels 12 are evacuated below atmospheric pressure they become less sound transparent, the

loss of transparency increasing with the degreeof evacuation.

Y Thus, by controlling the air pressure within the panels 12, control 'is' obtained over the volume of sound emitted from the swell box 2.

Mounted on the front panel 4 of the swell box 2 is a control unit 32, comprising a valve body 34 having a hollow vacuum manifold 36 secured thereto. The valve body 34 has a plurality of control bores 38 therethrough, one being disposed opposite each panel 12, and a passage 40 leads from the central portion of the wall of each control bore 38 to a valve port 42. Each 7 panel 12 has a port 44 in the end wall 20 thereof, and a conduit 46 connects each panel port 44 with its associated valve port 42. z v

The panel 4 has an opening 48 therein behind each control bore 38 to communicate the same .with atmosphere, and received within each control bore 38 is a spool valve element 50 having inner and outer sealing discs 52 and 54, respective ly, thereon. The confronting faces of the discs 52 and 54 are spaced apart a distance greater than the length of the control bore 38, and each spool element 50 is connected to a solenoid element 56.

The solenoid elements 56 each include a spring 58, which biases the spool 50 to seat the sealing disc 54 on the outer valve seat 60 surrounding the outer end of the central bore 38 when the solenoid 56 is not energized. Under these conditions, the interior of the panel 12 isopen to the vacuum manifold 36, from which air is withdrawn through a conduit 62 connected with an evacuating unit 64. Thus, when the evacuating unit 64 is operating and the solenoid 56 is not energized, the panel 12 will be under evacuation and will lose its sound transmission capabilities.

When the solenoid 56 is energized, the outer spool disc 54 will move free of the seat 60, and instead the inner disc 52 will engage the seat 66 surrounding the inner end of the control bore 38. This opens the interior of the panel 12 to atmosphere, whereby it is placed in its sound transparent state.

The solenoids 56 are all connected to suitable control mechanisms on the organ console (not shown), from whence they can be operated. The degree of evacuation of the panels l2can be controlled, but typically they will be evacuated to from 3 inches to inches water pressure on a manometer. The six panels in FIGS. l-4, being of equal size if evacuated to the same vacuum, can produce seven different volumes of sound, from a minimum when all panels are evacuated, to a maximum when all six are in a sound transparent state.

The control unit 32 is designed to operate the six panels 12 so that all are evacuated to the same extent 'lhe control apparatus can be modified so that any panel can be evacuated to the extent desired, which renders each panel adjustable over a wide range of volumes. This occurs because the degree of sound transparency is proportional to the extent of evacuation. With this arrangement, adequate volume control might be obtainable with fewer panels, perhaps even with a single panel 12. i

The honeycombed core 22 functions under evacuation to prevent inward movement of the membranes 24. Thus, the volume of the hollow panels 12 is held constant under evacuation.

Another panel arrangement is shown in FIG. 5, wherein seven degrees of organ volume are obtained with butthree panels, all of which are evacuated by a common evacuation unit 64' to a common vacuum level. In FIG. 5,, a swell box 2 is fitted with three anels 12A, 12B and 12C, each constructed like the panels 1 in FIGS. 1-4, but being each of a different height. The panels 12A, 12B and 12C are connected toa control unit 32, and are arranged to be operabie'independently or in any desired combination.

Given the same degreeof evacuation. andthe same length and thickness, the degree of volume transmitted bythe panels 12A, 12B and 12C isproportional to .the'airea s of: the membranes 24A, 24B and 24C thereon. Thus, s ince s everi different combinations are possible with the three panels 12A, 12B and 12C each of a different membrane area, seven different levels of organ sound can be had. i 1

It is to be understood that while one specific embodiment of the panels 12 has been shown and described herein, other structural arrangements are possible without departing from the invention. For example, depending on the flexure characteristics of the membrane material and the size of the panels, it might be possible to eliminate the honeycomb core 22. In addition, the individual frames 14 for each panel 12 might be combined into a common frame for allthe panelsof an assembly 10, or another arrangement for supp'orting'the membranes 24 might be devised.

The whole swell box canbe made of the hollow panels, thus allowing more sound to emit than through'one or more open sides. Also, the swell box may be a chamber'o'r room which includes the pipes, or a portion of a room.

It is further contemplated that this invention would be applicable to other types of volume control, for example, in con nection with room dividers that can block sound but allow outside light to pass through and also in connection with volume controls relating to electronic amplification, laboratory treatment and control, etc. In addition, it should be noted that the degree of volume blockage is both proportionate to the degree of vacuum and to the thickness of the panel, i.e., a high vacuum and thin panel would equal a low vacuum and thick panel. I

Obviously, many modifications and variations are possible, without departing from the invention as shown and described.

I claim:

1. In an organ swell box having a sound opening therein, means mounted within said sound opening for controlling the amount of sound emitted from said swell box, comprising: at least one panel mounted within said sound opening, said panel including: frame means; a pair of spaced membranes mounted on said framemeans, said frame means and said membranes defining a sealed chamber; and port means communicating with said sealed chamber, said panel being transparent to sound when the pressure therewithin admitted through said portmeans is 'at least equal to atmospheric, and becoming progressively less sound transparent as the pressure therewithin is decreased below atmospheric by evacuation through said port means.

2. In an organ swell box as'recited in claim 1, including additionally means connected to said'port means, operable selectively to admit atmospheric pressure to said chamber and to evacuate air therefrom.

3. .In an organ swell box as recited in claim 1, including a plurality of panels mounted within said sound opening; and means connected with each of said panels operable selectively and independently to admit air pressure to the chambers of said panels and to evacuate air therefrom.

4. In an organ swell box as recited in claim 3, wherein panels are identical in size and membrane area.

5. In an organ swell box as recited in claim 3, wherein said panels each have a different membrane area.

6. In an organ swell box'as recited in claim 1, wherein a honeycombed core is disposed within said chamber and extends between the confronting surfaces of said membranes.

said 

